1. Technical Field
Aspects of the present invention relate to an object detector, and more particularly relate to an object detector for use in a passenger conveyor system, wherein the object detector uses structured light to make a determination as to whether a passenger is disposed within a detection area.
2. Background Information
A passenger conveyor system (e.g., an escalator system, a moving sidewalk system, etc.) typically includes a passenger conveyor (e.g., a moving staircase, a moving sidewalk, etc.) that is operable to be driven by a drive machine. A passenger conveyor system typically can be operated in at least three operation modes, including: (i) a shutdown mode, in which the drive machine is powered off; (ii) a standby mode, in which the drive machine is powered on but is not driving the passenger conveyor, or is driving the passenger conveyor at slow speed; and (iii) a running mode, in which the drive machine is powered on and is driving the passenger conveyor. In some instances, a passenger conveyor system is continuously operated in a running mode, even when there are no passengers on the passenger conveyor. This can cause a significant amount of energy to be wasted. In some instances, a passenger conveyor system is continuously operated in a running mode because it lacks the ability to automatically switch between the various operation modes. To eliminate the need for manual switching between the various operation modes, safety codes (e.g., EN 115) permit the use of devices for automatically switching between the various operation modes. However, because it can be dangerous to switch between the various operation modes when a passenger is present on the passenger conveyor, safety codes require that those devices be operable to make a determination, with near absolute certainty, as to whether a passenger is present on the passenger conveyor. Devices have been developed that can make such a determination with sufficiently high certainty to comply with safety codes; however, those devices can be prohibitively expensive. Further, it would be desirable to be able to automatically switch from a shutdown mode to a running mode, or from a standby mode to a running mode, as a passenger approaches the passenger conveyor system; however, known devices for automatically switching between the various operation modes are unable to make a determination as to whether a passenger is approaching the passenger conveyor system. Aspects of the present invention are directed to these and other problems.